Free New Hampshire CDL Doubles & Triples Test Practice Test

Sample CDL Doubles & Triples practice questions

Try a few representative questions below. Each includes the correct answer and a short explanation — the same style you'll see in the full practice test.

1. Question 1Driving Maneuvers

   When driving a triple trailer combination at highway speeds, which of the following is the most critical factor to consider when planning for a lane change on a multi-lane highway, assuming all lanes are of equal width?

   • A.The reduced braking effectiveness due to the increased mass, requiring earlier braking.
   • B.The aerodynamic drag created by the trailing trailers, which can cause instability.
   • C.The total length of the combination and the need for a significantly larger gap than a single vehicle.(Correct)
   • D.The potential for trailer sway in the rear-most trailer due to wind gusts.

   Explanation

   The total length of a triple trailer combination can exceed 100 feet. This extreme length requires a much larger gap to complete a lane change safely compared to shorter vehicles. While other factors like braking and wind are important, the primary concern for a lane change is ensuring sufficient space for the entire length of the rig.

2. Question 2Loading and Stability

   You are hauling two 40-foot trailers. The front trailer is loaded to its maximum legal weight, and the rear trailer is loaded to 75% of its maximum legal weight. You encounter a downgrade. What is the primary concern regarding trailer tracking and stability in this scenario?

   • A.The front trailer, being heavier, will exert more force, potentially causing it to lose traction.
   • B.The articulation point between the trailers is under increased stress due to uneven loading.
   • C.The air brakes on the rear trailer may not be sufficient to control the combined momentum.
   • D.The lighter rear trailer is more susceptible to being pushed by the front trailer, increasing the risk of jackknifing.(Correct)

   Explanation

   When descending a grade, the front trailer, being heavier and more loaded, will tend to push the rear trailer. If the rear trailer is lighter, it has less traction and is more prone to skidding or jackknifing, especially if braking is applied unevenly or too aggressively. The heavier front trailer's momentum can overwhelm the lighter rear trailer's stability.

3. Question 3Driving Maneuvers

   You are performing a low-speed, tight-turn maneuver with a triple trailer combination. You observe the rear-most trailer beginning to swing out wider than anticipated. What is the most effective immediate counter-action?

   • A.Steer slightly in the opposite direction of the turn to bring the rear trailer back in line.(Correct)
   • B.Slightly accelerate to straighten the trailers and then gently steer to correct.
   • C.Straighten the steering wheel momentarily to allow the trailers to realign.
   • D.Apply a light, steady pressure to the trailer brakes to slow the rear trailer.

   Explanation

   When the rear-most trailer begins to swing out wide during a turn, it indicates that the combination is trying to 'cut the corner' too sharply. Steering slightly in the opposite direction of the turn (counter-steering) helps to guide the rear trailer back into its proper path and prevents it from hitting curbs or other obstacles. This is a common technique for managing multi-trailer tracking.

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